[ On Tuesday, August 27, 2002 at 10:02:14 (+0100), David Laight wrote: ]
> Subject: Re: HEADS UP: migration to fully dynamic linked "base" system
>
> There is absolutely nothing to stop a statically linked program
> using mmap to get a piece of writable, executable memeory.
> Code can be written to it and then executed [1].
That might be true today (because mostly with an executable stack
there's no point to preventing it, and of course it's a necessary
feature for the existing shared library support), but unprivileged
access to use the PROT_EXEC flag is something that's trivial to turn off
if one doesn't need or want to support the current regime of shared
libraries.
--
Greg A. Woods
+1 416 218-0098; <g.a.woods@ieee.org>; <woods@robohack.ca>
Planix, Inc. <woods@planix.com>; VE3TCP; Secrets of the Weird <woods@weird.com>